This invention relates to an electronic card receiving device for receiving a card in which integrated circuits are incorporated to have electronic functions, which is referred to as an "electronic card" hereinafter, and more particularly to a card inserting and removing mechanism and a card connecting mechanism for the electronic card receiving device.
As the integrated circuit technique has been developed in recent years, it has become to realize integrated circuits on a great scale in a small chip, so that various kinds of electronic cards having high degree functions have been developed so as to be used in wider applications.
FIG. 1 illustrates one of such an electronic card which comprises a non-volatile memory a, i.e. ROM or RAM capable of electrical writing and reading, a central processing unit (CPU) b for controlling operations of the ROM or RAM, a substrate c in the form of a card in which the ROM or RAM and CPU are embedded, contacts d for connection with external electronic instruments. When such an electronic card is used, it is inserted into an electronic card receiving device attached to an external device of an electronic computer or its terminal equipment.
FIGS. 2a-2d schematically illustrate a construction of an electronic card receiving device showing respective conditions, before insertion of a card (FIG. 2a), during insertion (FIG. 2b), just inserted and electrically connected (FIG. 2c), and during removal of the card (FIG. 2d). The device illustrated in FIGS. 2a-2d is submitted as background information of the Assignee of the present invention which is known within the Assignee's organization but was unknown to the public.
The electronic card 16 is inserted into the receiving device in a direction shown by an arrow A as shown in FIG. 2a. The card 16 is advanced into the device, pushing downward a card guide 21 as shown in FIG. 2b. As a result, a card latch 20 moves downward together with the card guide 21, so that contacts 26 in the form of rods of a circuit board 27 attached to the card latch 20 move downward away from a surface of a card holder 15. FIG. 2c illustrates when the electronic card 16 has completely passed by the card guide 21 and has been received in a card receiving chamber. At this moment, the card latch 20 is raised by a spring force of a spring 31, so that the card guide 21 closes an inlet of the card receiving chamber, and the card 16 is fixed in position with respect to the card holder 16 by a reference surface 22 of the card guide 21 cooperating with the urging spring 31. Moreover, as the card latch 20 has been raised, the rod-like contacts 26 of the circuit board 27 attached to the card latch 20 extend beyond the surface of the card holder 15 so as to be connected to contacts of the electronic card to obtain a condition ready for communication.
When it is desired to remove the electronic card from the card receiving device, a reject key 35 extending out of a housing 1 of the device is pushed in a direction shown by an arrow in FIG. 2d. By depressing the reject key 35, the card guide 21 and the card latch 20 start to move downward as shown in the drawing, so that the contacts 26 of the circuit board 27 attached to the card latch 20 move also downward away from the contacts of the card 16 below the surface of the card holder 15. Further, when the card guide 21 is lowered at the level of the surface of the card holder 15, the electronic card 16 is pushed out of the device by a spring force of a leaf spring 33 provided in the card receiving chamber.
The electronic card receiving device above described has such superior functions that when the electronic card is being inserted thereinto or removing therefrom, the contacts of the electronic card do not rub each other and when the electronic card is once accommodated in the device, the card is securely fixed in position relative to the card holder 15 with the aid of the leaf spring 33 and the reference surface 22 of the card guide 21.
However, the device as above described which solves various problems has still further problems as follows.
As such electronic cards have been widely used, there is a tendency for the cards to be roughly handled by users. Moreover, surfaces of terminals of the electronic cards are not necessarily flat and are often distorted due to bending or twisting of the cards. Accordingly, contact terminals of card receiving devices frequently do not completely contact the surfaces of the terminals of the electronic cards. In order to prevent this, it has been proposed to provide a strong spring as a spring corresponding to the spring 31 shown in FIG. 2a. However, such a strong spring tends to damage the contact terminals of the devices and the surfaces of terminals of the electronic cards, so that a high reliability of the devices based on such as million times of insertions and removals of the cards cannot be obtained. In case of a great number of terminals with narrow intervals, particularly, it is difficult to manufacture high reliable contacts in flat and small forms.
In the card receiving device as above described, when an electronic card is removed from the device, the card latch 20 is pushed down by manually pressing the reject key 35 to move the electronic card 16 out of the device with the aid of the leaf spring 33.
With this arrangement, the electronic card 16 is pushed out of the device as soon as the reject key 35 is pressed. On the other hand, the reject key 35 is often pressed, for example, during writing or reading of the ROM and RAM in the electronic card or the reject key 35 is frequently unintentionally pressed, so that such a mishandling causes the ROM and RAM to be damaged or at least the contents of the ROM and RAM to be abnormal.
Moreover, the electronic card is pushed out of the device by means of the leaf spring 33. However, it is difficult to provide a long stroke distance of the leaf spring 33. If a distance by which the electronic card is moved out of the device is made sufficient, the leaf spring is subjected to an overload which would prematurely fatigue the leaf spring.